The invention relates to an imaging unit in a printing press.
A printing press with a printing unit having a seamless image cylinder, which is coated with a dryable polymer by a direct image creation process in the printing unit is known from German patent NO. 19612927 Al.
The surface characteristic of the dryable polymer on the image cylinder is completely converted or only in certain areas by a selective laser exposure after drying to change its affinity to a printing ink. In a conventional printing press either in wet offset printing or in dry-offset printing the image cylinder is used instead of the plate cylinder. The image cylinder is cleaned of the image carrying layer after the printing. This layer must not be totally removed.
The laser source, the coating unit and the drying unit are mounted side by side on a spindle drive. They are moved according to the rotation of the spindle over the width of the cylindrical imaging surface. The cleaning unit is separately allocated.
The lacking of complexity of the apparatus and necessary unproductive time during reversing of the spindle drive represent disadvantage.
It is an object of the inventions to provide a compact imaging unit with a short operating time.
That object is solved according to the present invention by allocating the coating unit, the image creation unit and the developing unit together one below the other in a traversing imaging unit.